Ukrainian President Volodymyr Zelensky has said he is willing to release North Korean soldiers captured by Ukraine in the Kursk region of Russia in exchange for Ukrainian soldiers being held captive in Russia.

South Korea’s spy agency has told lawmakers that two North Korean soldiers captured by Ukrainian forces while fighting alongside Russian forces in Russia’s Kursk border region haven’t expressed a desire to seek asylum in South Korea.

North Korean soldiers sent to bolster Moscow’s forces after Ukraine launched a lightning-fast incursion and seized territory in Russia’s Kursk region over the summer.